diff options
| -rw-r--r-- | fs/overlayfs/readdir.c | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 01620ebae1bd..60d751f28fea 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -865,7 +865,7 @@ struct file *ovl_dir_real_file(const struct file *file, bool want_upper) struct ovl_dir_file *od = file->private_data; struct dentry *dentry = file->f_path.dentry; - struct file *realfile = od->realfile; + struct file *old, *realfile = od->realfile; if (!OVL_TYPE_UPPER(ovl_path_type(dentry))) return want_upper ? NULL : realfile; @@ -874,29 +874,20 @@ struct file *ovl_dir_real_file(const struct file *file, bool want_upper) * Need to check if we started out being a lower dir, but got copied up */ if (!od->is_upper) { - struct inode *inode = file_inode(file); - realfile = READ_ONCE(od->upperfile); if (!realfile) { struct path upperpath; ovl_path_upper(dentry, &upperpath); realfile = ovl_dir_open_realfile(file, &upperpath); + if (IS_ERR(realfile)) + return realfile; - inode_lock(inode); - if (!od->upperfile) { - if (IS_ERR(realfile)) { - inode_unlock(inode); - return realfile; - } - smp_store_release(&od->upperfile, realfile); - } else { - /* somebody has beaten us to it */ - if (!IS_ERR(realfile)) - fput(realfile); - realfile = od->upperfile; + old = cmpxchg_release(&od->upperfile, NULL, realfile); + if (old) { + fput(realfile); + realfile = old; } - inode_unlock(inode); } } |